Hall Constant of Strongly Correlated Electrons on a Ladder

The Hall constant R-H in a tight-binding model of correlated electrons on a ladder at T = 0 is expressed in terms of derivatives of the ground state energy with respect to external magnetic and electric fields. This novel method is used for the analysis of the t-J model on finite size ladders. It is found that for a single hole R-H is holelike and close to the semiclassical value, while for two holes it can vary with ladder geometry. In odd-leg ladders, R-H behaves quite regularly changing sign as a function of doping, the variation being quantitatively close to experimental results in cuprates.